Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L19/00—Compositions of rubbers not provided for in groups C08L7/00 - C08L17/00
  • C08L19/003—Precrosslinked rubber; Scrap rubber; Used vulcanised rubber
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J11/00—Recovery or working-up of waste materials
  • C08J11/04—Recovery or working-up of waste materials of polymers
  • C08J11/06—Recovery or working-up of waste materials of polymers without chemical reactions
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/12—Powdering or granulating
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2300/00—Characterised by the use of unspecified polymers
  • C08J2300/30—Polymeric waste or recycled polymer
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2319/00—Characterised by the use of rubbers not provided for in groups C08J2307/00 - C08J2317/00
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2321/00—Characterised by the use of unspecified rubbers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/62—Plastics recycling; Rubber recycling
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
  • Y10T428/2991—Coated
  • Y10T428/2998—Coated including synthetic resin or polymer

Definitions

• the present invention relates to rubber granulates, in most cases from recycled rubber tires, used with success as infill material in the top layer of artificial grass football grounds.
• Kuraray Co., Ltd., C.A. 98:157436t discloses beads, particles, fibres, sheets, and tubes of glass, activated carbon, silica, alumina or high molecular weight substances coated with copolymers of acrylates and carboxylic acids or amines to form selective adsorbent carriers or supports for use in selective electrodes or in column chromatography.
• Sakuma et al., C.A. 111:74363c disclose glass or polymer spheres coated with hydroxyapatite for use as a stationary phase for column chromatography.
• EP-A-0266580 discloses a method for coating solid particles with a hydrophilic gel preferably agarose for various separating processes in packed columns based on adsorbent groups, e.g. ion exchanging groups, hydrophobic groups, or groups with biospecificity chemically bound to a gel.
• adsorbent groups e.g. ion exchanging groups, hydrophobic groups, or groups with biospecificity chemically bound to a gel.
• Such coating may be provided by mixing hydrophilic solid particles with a gel-forming substance above the gelling temperature in which each individual particle is coated, separated from each other, and cooled below the gelling temperature, essentially to stabilize the particles against the high pressure in e.g. HPLC applications.
• coated particles are provided by coating individual particles made of the same material.
• U.S. Pat. No. 4,698,317 discloses hollow microspherical glass particles having open pores, and being prepared by spray thermal decomposition of a solution, in an aqueous organic solvent, wherein the water content promotes open pore formation.
• U.S. Pat. No. 2,797,201 discloses substantially spherical, hollow particles having a “thin, strong skin” being prepared by thermal treatment of droplets of a solution of a film forming material, e.g. an organic polymer such as a phenol formaldehyde resin, and optionally further containing a “blowing agent”, i.e an agent generating gas at the elevated temperature of the thermal treatment.
• a film forming material e.g. an organic polymer such as a phenol formaldehyde resin
• a “blowing agent” i.e an agent generating gas
• GB 2151601B discloses porous hollow particles of an inorganic material and a composite material comprising such particles supporting a selected substance such as a chromatographic organic gel.
• the porous hollow particles may be formed by coating a fugitive core material, e.g. organic resin beads or alginate spheres, with inorganic material, and then heating to remove the fugitive core material.
• GB 2151602B discloses closely similar particles wherein a magnetic material, such as ferric oxide, nickel oxide or cobalt oxide, is incorporated in the inorganic shell of the particle.
• GB-A-2196252 discloses an oral, solid, pharmaceutical dosage form comprising conventional matrix binders including starch and cellulose, or their derivatives, and a pharmaceutically acceptable weighting agent, including inorganic compounds such as salts, oxides, or hydroxides of a metal, e.g. barium sulphate or ferrous oxide, suitable for oral administration to humans and for controlled release of a pharmaceutically active ingredient into the stomach.
• a pharmaceutically acceptable weighting agent including inorganic compounds such as salts, oxides, or hydroxides of a metal, e.g. barium sulphate or ferrous oxide, suitable for oral administration to humans and for controlled release of a pharmaceutically active ingredient into the stomach.
• the described pharmaceutical dosage form consists of solid particles comprising a binder and a weighting agent soluble in gastric fluid which makes the pellet or tablet disintegrate shortly after ingestion.
• U.S. Pat. No. 4,142,969 discloses an oleo specific hydrophobic composition
• the constituents are incorporated into a homogeneous product by a wet process, dried in an oven until essentially all moisture has been removed, and then ground up into a fluffy low density material.
• WO 00/78852 A2 discloses a process of fine rubber aggregation with a polymeric binder.
• the product is in this case one aggregate and not individual particles, and the process used is completely different from the one disclosed in the present invention.
• EP 1422 345 A1 discloses a process for the coating of sand granules. It does not include rubber and the process is completely different since it involves the melting of the coating mixture rather than the surface cross linking of the wet film.
• U.S. Pat. No. 4,381,354 discloses a process of coating sand and the process discloses is different from the one of the present invention since one halogenated compounds are used and also a metal powder.
• WO 02/097194 A1 refers to a plastic flake aggregated by a binder to form final particles, but both the material and the process are different from the one considered in the present invention.
• Rubber granulates impart to the top layer the required resilience and “natural grass feeling” but present, so far, a number of draw back, partly overcome by the present invention.
• Attrition by the players further increase mechanical abrasion with resulting dust formation.
• composition of rubber for tires included polyaromatic oils, benzotiazol derivatives and zinc compounds that slowly leach from the granules to the soil.
• Polyaromatic oils are nowadays of special concern due to the presence of carcinogenic components that can migrate through the skin in case of prolonged contact.
• Polymeric films were first prepared on glass surfaces to correlate Barrier properties with composition for the relevant range of thickness 10 micron to 80 micron.
• Covered particles are virtually dustless, flame retardant, with improved U.V. and ozone resistance, and the barrier effect of the covering layer reduces leaching of zinc and organic compounds.
• the present invention relates to a process of covering rubber particles with a highly adherent functional layer of polymer, and the resulted covered particles.
• the process includes a pre-blend of ingredients a) to f) in one extensive mixer, followed by mixing with the rubber granulates.
• a variable speed rotating reactor with internally fixed blades is initially filled with the rubber granulate and rotation started at low speed (below 10 turns by minute).
• the pre-blend with adjusted viscosity and setting time is added gradually over the rubber under continuous rotation, in tree steps.
• Rotating speed as well as axis angle is then adjusted step by step to minimize agglomeration of the rubber.
• the process is therefore a surface coverage film by covalent bounds to the rubber surface.
• Samples taken at intervals allow for the control of residual tackiness and the reactor is discharged once the residual tackiness is no further detected.
• Montemovillonite clay was used both as opacifier and also for its synergic effect, boosting the flame retardancy.
• the first object of the invention is a process for covering rubber particles with a continuous functional layer of polymeric nature, which use a rotating drum with variable speed drive allowing for a progressive reduction of the speed and a pre-blend of a setting and filmifiable reactive fluid comprising a liquid resin selected from alkyd resins, polyvinyl chloride resin, urethane alkyd resins, polyurethane-urea resins and reactive polyester resins.
• the rubber particles to be covered have, usually, average dimensions from 0.1 mm average radius to 5 mm average radius, preferably 0.5 mm to 2.5 mm.
• the pre-blend used for coverage comprises additionally one drying component with cross linking action.
• the cross linking component is preferably, selected from poly functional isocyanates, hydrophobic ketene dimmers, isocyanate quasi-prepolymers and polyacrylchlorides.
• the pre-blend used for coverage comprises additionally an oleophilic organic pigment, a flame retardant, a flexibilizer oleophilic oil and an ultra violet radiation protector.
• the second object of the invention is the covered rubber granulates, obtained by the above process, which comprise rubber granulates covered with a pre-blend of a setting and filmifiable reactive fluid comprising a liquid resin selected from alkyd resins, polyvinyl chloride resin, urethane alkyd resins, polyurethane-urea resins and reactive polyester resins.
• the covered rubber granulates has, normally, a thickness over 30 micron, preferably over 50 micron, in order to be a very effective barrier to polyaromatic oils, zinc, and other mobile components of the rubber granulate.
• the covering film has high adherence and similar flexibility to the rubber, improving the abrasion resistance of granulate.
• the colored layer of the covered rubber granulates does not suffer significant color change under exposure to ultraviolet radiation, namely under xenon lamp radiation.
• the final covered particles present improved sphericity and shape regularity due to liquid surface tension before setting and virtually dustless due to small particles and powder aggregation in the wet film.
• the resulting liquid mixture is applied within a 10 minutes period to the rubber granulate, in the rotating drum and the speed of rotation is progressively reduced to avoid particle agglomeration. Rotation is however kept until tock free surface of the granulate. A dustless green granulate is obtained.
• the resulting liquid mixture is applied within a 12 minutes period to the rubber granulate, in the rotating drum, and the speed of rotation in progressively reduced to avoid particle agglomeration.
• Hot air is then blowed in the rotating drum until the covered rubber particles are tack free.
• a dustless green granulate is obtained.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Processes Of Treating Macromolecular Substances (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

Country Status (6)

Cited By (3)

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Citations (7)

Family Cites Families (3)

• 2008
  • 2008-07-31 PT PT104150A patent/PT104150A/pt not_active Application Discontinuation
  • 2008-09-26 US US13/056,850 patent/US20110189485A1/en not_active Abandoned
  • 2008-09-26 EP EP20080813052 patent/EP2337812A1/en not_active Withdrawn
  • 2008-09-26 BR BRPI0822974-0A patent/BRPI0822974A2/pt not_active IP Right Cessation
  • 2008-09-26 WO PCT/PT2008/000037 patent/WO2010014024A1/en active Application Filing
  • 2008-09-26 CA CA 2732691 patent/CA2732691A1/en not_active Abandoned

Patent Citations (7)

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